Controlled sudsing heavy duty liquid detergent



United States Patent Of ice CONTROLLED sunsmo HEAVY DUTY LIQUIDDETERGENT Vincent Lamberti, Hackensaclr, and Arthur 0. Gray, Jr.,

River Edge, N. J., assignors to Lever Brothers Company, New York, N. Y.,a corporation of Maine No Drawing. Application July 25, 1957 Serial No.674,048

4 Claims. (Cl. 252-137) The present invention relates to detergentcompositions, and more particularly to controlled sudsing heavy dutyliquid detergent compositions which have phase stability on storage.

Many detergent compositions have heretofore been prepared, but they haveprimarily been in a powdered form and thereby have many disadvantagesenumerated below. Powdered detergent compositions are generally preparedby spray drying or drum drying, which are costly operations. When usedin washing, the powdered detergent compositions must be dissolved toform dilute aqueous washing solutions. This step of dissolving ordispersing the powdered detergent compositions in the wash water is timeconsuming. Frequently, the powdered detergent compositions aredifiicultly dispersed, since they may tend to form lumps. Powdereddetergent compositions, moreover, tend to vary greatly in density unlessparticular care is taken in their preparation. Such a variation indensity makes it difiicult to determine the exact amount thereof to beemployed during washing. In addition, powdered detergent compositionsmay be difficult to dispense, since they sometimes clog the orifices ofa dispenser. Also powdered detergent compositions have a tendency tocake at high humidities upon standing intheir own containers. Moreover,powdered detergent compositions, being normally sold in cardboardcontainers, are subject to spilling and waste in the event an opencontainer is accidentally knocked over. Furthermore, their dustiness maybe bothersome, particularly to persons who suffer from dust allergies.

All of. these disadvantages of powdered detergent compositions can beobviated by employing concentrated liquid detergent compositions. Whilelight duty liquid detergent compositions have been prepared heretofore,they have proved to be suitable only for dishwashing and the cleaning offine fabrics. Light duty, liquid detergent compositions areunsatisfactory for washing heavily soiled cotton fabrics, since suchcompositions have inadequate soil removal characteristics. Heavydutyliquid detergent compositions, on the other hand, have excellent Isoil removal characteristics and. are ideally suited for the,washing ofheavily soiled cotton fabrics and other fabrics. v

A heavy duty liquid detergent must be homogeneous in composition at thetime of addition to the washing machine in order to insure that thewashing solution will contain the proper ratio of ingredients. Theconsumer buys a detergent product after it has been subjected to varioustemperatures and conditions of storage between the time of productionand arrival on the dealers shelves. These various storage conditionshave greater adverse eifect on a liquid product containing a delicatelybalanced active detergent and cellulosic suspension than on a detergentpowder.

A heavy duty liquid detergent designed for use in both horizontal (frontloading) and upright (top loading) washing machines must have acceptablesudsing and loading horizontal tumbler type automatic washers, theseproducts foam profusely causing the tumbler to fill or overflow withdense suds. These dense suds impede the washing action by interferingwith the free fall of clothes in the tumbler and may strain the workingparts of the machine to cause slowing or stalling, further impedingwashing action, and causing excessive wear of machine parts. When usinghigh sudsers in this type of washer, the housewife is inclined to reduceusage level in order to eliminate this excess sudsing. The amount ofproduct thus used is frequently insufficient to wash elfectively or toprovide the desired level of optical brightener.

Profuse sudsing in top loading vertical agitator-type automatic washersdoes not interfere with washing action, but may tend to cause suds-lockduring the extraction cycle. Suds-lock prevents efficient extraction ofwater from the clothes by slowing or stalling the machine, and alsocauses excessive wear of'machine parts.

A low-sudsing detergent product will produce no suds coverage when usedin an upright washing machine. This lack of suds coverage does notobscure the dirty water from view and leads to the impression that toolittle product was used. The consumer may add more product in an attemptto obtain suds coverage. Such overuse of the product is uneconomical andmay be reflected in failure of the consumer to repurchase.

Accordingly, it is an object of the present invention to provide heavyduty liquid detergent compositions which have controlled suds, i. e.,there is neither a high amount nor a low amount of suds, but rather amedium amount of suds. It is a further object of the invention toprovide heavy duty liquid detergent compositions in which the amount ofsuds produced therefrom is stable over a relatively prolonged period,especially in the presence of soil. It is also an object of theinvention to provide heavy duty liquid detergent compositions which havephase stability, i. e., there is aminimum of separation of the variouscomponents therein upon storage.

The above objects have been accomplished by formulating heavy dutyliquid detergent compositions having various critical factors whichinclude the number of the components making up the compositions, thenature of the components present therein, and the amounts of thecomponents utilized therein. The compositions of the invention consistessentially of aqueous suspensions of various components as furtheridentified below.

The compositions contain as an active detergent component potassiumdodecylbenzene sulfonate in an amount from about 2% to about 3%. Thepotassium dodecylbenzene sulfonate supplies a portion of the foaming andponent which is used in an amount from about 22.5% to about 25% suppliesthe heavy duty detergent feature of the liquid and imparts good soilremoval properties thereto.

The compositions also contain from about 2% to about 3% of an alkalimetal xylene sulfonate, such as sodium xylene sulfonate or potassiumxylene sulfonate.

Patented Nov. 11, 1958' Thexylene sulfonate acts as a hydrotrope insolubilizing the. active detergent components of thecompositions in thepresence of a considerable amount of the polyphosphate and any otherinorganic materials.

There is also present in the compostions about. 1%

of coconut oil fatty acids, i. e., the naturally occurring mixtureof.fatty acidspresent incoconut oil, as well as about 1% ofthe-condensation product of one moleof lauric monoethanolamide with onemole of'ethylene oxide, and about 1% of triethanolamine. Thesecomponentstogether aid in impartingphase stability and suds stability tothe heavy duty liquid detergentcompositions.

The-compositions ofthe invention also contain a'pair of cellulosic'soilsuspending agents which form a uniform, stable suspension therein evenunder adversev storage conditions Thispair ofcellulosic soil suspendingagents consists of. about 0.3% 'offsodium carboxymethylceliulose andabout 0.7% of Methocel. The sodium carboxymethylcellulose contains. 0.7mole of carbox-ymethyl groups. peranhydroglucose unit. Methocel. is atrade namefor methylcel'lulose of. 25 centipoise viscosity in a acids,the condensation product of one mole of lauric monoethanolamide with onemole of ethylene oxide the triethanolamine, and any optical brighteners,and tetrapotassium pyrophosphate. The compositions are completed by theadjustment with alkali to a pH of about 12 followed by the addition ofthe alkali metal silicates.

The controlled sudsing heavy duty liquid detergent compositions of theinvention having, phase stability on storage and suds stability onusagewill be further illustrated by the following examples.

The compositions of the invention were prepared'as were othercompositions in which various components-of the compositions of theinvention were omitted in order to demonstrate forcefully thecriticality of the presence of the various components inthecompositions. These compositions are set forth below in Table Iwherein Compositions X, X, and X" are the compositions of the inventioncontaining various optional components, namely sodium silicate,potassium hydroxide; andi fluorescent dye, while Compositions A throughF arezcomparative: compositions wherein various componentsofthecompmsitions of the invention were omitted.

TABLE I Components Compositions (Percent by Weight) Fluorescent Dye(Uvitex SI) Fluorescent Dye (1:1 mixture of U Oaleofiuor White MR) i.Water, Miscellaneous Salts, and Potass m droxide to pH 11.8

2% aqueous dispersion having 27.5-32% methoxyl groups per cellulosemolecule.

The remaining essential component of the heavy duty liquid detergentcompositions is water which-servesas a solvent for the solublecomponents thereof.

If desired, .theheavy duty liquid detergent compositions may containminorportions of an alkali, such as potassium hydroxide, to neutralizeany excess acid impurities present in V the components of thecompositions. -In addition, minor portionsof' compatible perfumes,fluorescent dyes, optical brighteners,.alkali metal silicates, and otherdesirable adjuvants may be added to the compositions. When awater-soluble alkali metal silicate is added to the compositions, the pHthereof must be adjusted to about 12. by the addition of free alkali,such as potassium hydroxide, to keepthe silicate in solution.TypicaLalkali metal. silicates include the-sodium or potassium silicateshaving the. following alkali to silica ratios: 1:3.92, 1:3.44, 1:3.25,1:2.5, 1:2.4, 1:2.0, 1:1.8, and 1:1. Generally, about 3% of the alkalimetal silicate is employed. The amount of perfumes, fluorescent dyes,and optical brighteners, is'quitesmall and generally is about 0.1% orless.

The controlled sudsing heavy duty liquid detergent compositions of. theinvention may be prepared bymixing the components thereof together inthe aqueous medium. Heat. maybe-conveniently utilized during the mixingof the components toincrease the rate of dissolution thereof. Apreferred methodfor the preparation of the compositions isthe additionof the pair of cellulosic soil suspending agents to hot water followedby cooling to form an aqueous suspension thereof and the addition to thecellulosic suspension of an aqueous solution of thepotassium-dodecylbenzene sulfonate, the alkali metal xylene sulfonate,the sodium tallow methyl taurate, the coconut oil fatty Compositions X,X, and X" of the invention asgwelL as various comparative compositionswere testedfor phase stability under various conditions of storage. Alb

of the formulations were stored for seven days :atvarious.

storagetemperatures, namely 14 F., 35 F., roon1 tem-. In addition,samples;-

perature (70 F.), and F. of the formulations were subjected from 14 tofive daily cyclings F. to room temperature and from 35 F. to:

room temperature. After undergoing storage the samples were eitherunaffected, showed a rise or drop of cellulosics, or an unevencellulosic distribution, or. exhibited organic. phase separation. Inorder to facilitate comparison of various formulations the followingnumerical rating system was used:

Condition of sample after storage: 1 Numerical rates In the abovenumerical rating system rise or drop refersto the rise or drop of thecellulosic soil suspending agents. In any combination of conditions, thenumerical rating. numbers are additive, i. e., very slight. drop plusuneven cellulosics equals 0.1plus 0.5, or a total rating of 0.6.However, the maximum numerical rating in any one condition will be 6.0.The numerical rating for each of the tests conducted Were added to givea total rating. Of

stability. Moreover, the presence of tetrapotassium pyrophosphate isquite critical, since the substitution of pentapotassiumtripolyphosphate therefor produces compositions in which the cellulosicsoilsuspending agents course, the lower the total rating, the better isthe phase 5 are unstable and may cause the precipitation of silicastability of the composition. t from the compositions due to hydrolysisof this poly- Data on this phase stability test wherein Compositionsphosphate. X, X, and X of the invention were compared with Com- The sudsstabllity of the controlled sudsmg heavy duty positions A through F astypical comparative composiliquid detergent composit ons of theinvention was also tions are set forth below in Table II. 10 tested andcompared with other formulations WhlCh TABLE II Phase stabi ity testconditions and ratings Cycled Room Total Compositions 14 F 35 F. Temper-125 F. 35 F. to 14 F. to Rating ature Room Room Temper- Temperatureature .0 0.2 2 0 1.5 3.7 0.2 0.1 0.2 1.0 0 0.1 1.6 0.1 0.1 0.1 0.2 0.10.1 0.7 1 a. 6 0 6 0. a 36.0 4 4 5 0.2 5 5 23.2 3 0.5 0 0.1 0.2 1 4.3 I3 0 1.5 2 1 a 10.5 5 0.5 1.5 0 1.5 5 13.5 1.5 0 0 0.5 0 0.2 2.2

From the data set forth above in Table II it will be omitted variouscomponents of the compositions to show noted that Compositions X, X, andX of the invention 30 the criticality of the components in thecompositions of had lower total ratings, and hence better phasestability, the invention. In the suds stability tests, 0.25 gram of thandid any of the comparative compositions with the the detergentcompositions were each added separately exception of Composition Xversus Composition F. to l00 ml. of Water 1n 500 m1 glass stoppedgraduated Composition F, however, does not have the requisite cylinders.Each cyhnder was lnvertedt wenty nrnes suds stability in watercontaining soil as shown below 35 cycles from upright to uprlght)Initial suds volume in Table III and hence it does not have the balancedand suds volume at minute intervals for 45 minutes properties ofbothphase stabilityand suds stability that were recorded. Tests were run indistilled water at 120" are possessed by Compositions X, X, and X" f thF. Since the compositions of vtheinvention would norinvention, mally beused in automatic washers in which the water When various othercomponents of the compositions 40 would Contall} Soil, one p 0f oil wasfiof the invention were omitted therefrom, unstable com- Thef01'mll1at10nS tested Composltlon X of the positions were also obtained.The phase stability test V li a W as COmP IH HS A through F Set forthwas also run for compositions containing both less and above 111 Tabledata 011 11115 Suds stablllty test more of the tetrapotassiumpyrophosphates, i. e., are Set forth below 111 Table 1 and thereof, andmore and less of the detergent TABLEIH actives, i. e., potassiumdodecylbenzene sulfonate and sodium tallow methyl taurate. These phasestability tests Suds Volume of Compositions (milliliters) showed thatsuch heavy duty llquid detergent composi- Time Interval tions wereunstable and accordingly demonstrate the (minutes) X A B C D E Fcriticality as to the amount of these components which must be employedtherem' 250 220 200 210 160 125 210 Not only are the total number ofcomponents present 240 180 180 190 110 115 180 in the compositionscritical as well as the amounts theregig g2 g3 28 of, but also thenature of the components is quite critical.

Thus, various anionic and nonionic synthetic organic non-soap detergentswere substituted for an equal amount of the sodium tallow methyl tauratecomponent of the compositions and phase stability tests run thereon.When each of the following exemplary synthetic detergents was sosubstituted, the resulting formulations were unstable as determined bythe above phase stability test: potassium pentadecylbenzene sulfonate,Santomerse E (a mixture of potassium pentylbenzene sulfonate andpotassium hexylbenzene sulfonate), sodium lauryl sulfate, sodiumN-ethyl-N-palmitoyl taurate, sodium N-isopropyl-N-hexadecanoyl taurate,sodium N-methyl-N-oleyl taurate, the condensate of dodecyl phenol with13 moles of ethylene oxide, the condensate of propylene oxide withethylene oxide, sodium isopropyl naphthalene sulfonate, disodiurnN-octadecyl sulfosuccinate, potassium a-sulfopalmitate.

The presence of sodium Xylene sulfonate in the controlled sudsing heavyduty liquid detergent compositions of the invention is quite critical,since the substitution therefor of sodium toluene sulfonate or sodiumbenzene sulfonate' produced formulations having poor phase The data setforth in Table III above clearly show that representative Composition Xof the invention had far greater suds stability than did Compositions Athrough F in view of the small comparative decrease in sudsvolume over a45 minute interval. It will be appreciated that the compositions of theinvention are concerned with a system of suds which are controlled to alower level than is desired for non-automatic washers, so that theimportance of the data set forth above in Table III lies not in acomparison of the total suds volume, but rather in a comparison of thesuds stability or change in suds volume over a period of time.

The controlled nature of the suds produced by the compositions of theinvention is evident from the following data in Table IV below wherein2.6 ounces of Compositions X, X, and X were separately added to 8gallons of water containing soil and the height of suds on the port of ahorizontal or front loading Bendix Washer observed at 3, 6, 9 and 12minutes during the washing cycle. In this table the fractions refer tothe portion of the port coveredby the suds.

7 TABLE Iv Suds Volume Compositions a a as 1A Vi it a as 1 Whenhighsudsing' detergents were Similarly tested, they produced a profuseamount of suds at the end of only three minutes which completely coveredthe port of the washer.

In view of the above data it will be apparent that the heavy duty liquiddetergent compositions which have phase stability on storage and sudsstability in usage and thereby make them products ideally suited for usein automatic clothes washers. sudsing products do not produce excesssuds when used in horizontal washing machines, but they do givea;showing of suds on the water surface when used in vertical typemachines.

It will be appreciated that various modifications andv changes may bemade in the compositions of the invention without departing from thespirit thereof and accordingly the invention is to be limited onlywithin the scope ofthe appended: claims.

We claim:

- 1. A controlled. sudsingyheavy duty liquid detergent composition whichhas phase stability. on storage and suds stability-in usage consistingessentially of. an aqueous suspension of: from' about2% to about 3%ofpotassium dodecylbenz'ene sulfonate, abo.uti5% of sodium-tallow methyltaurate, from about 2%" to about 3% offanjalkali metal. xylenesulfonate,

about 1% of ,coconutoil' fatty acids, about 1% of the Moreover, thecontrolled from about 3.5% to 35 l compositions of the mvention providefor the first t1me m0 6 of ethylene Oxide about 1% condensation productof one mole of lauric monoethanolamide with one mole of ethylene oxide,about 1% of triethanolamine, about 0.3% of sodiumcarboxymethylcellulose, about 0.7% ofmethylcellulose, and from about22.5% to. about'25% of tetrapotassium pyrophosphate.

2. A controlled sudsing heavy duty liquid detergent composition whichhas phase stability on storage and suds stability in usage consistingessentially of an aqueous suspension of about 2% of potassiumdodecylbenzene sulfonate, about 3.5% of sodium tallow methyl taurate,about 2% of sodiumxylene'sulfonate, about 1% of coco nutnoilfatty.acids, about. 1% of the condensation prodnot of one mole of lauricmonoethanolamide with one of triethanolamine, about 0.3% of sodiumcarboxymethylcellulose having 0.7 mole of carboxymethyl groups peranhydroglucose unit, about 0.7% of methylcellulose of 25 centipoise Iviscosityin a 2% aqueous dispersion having 27.5-32% methoxyl groups'percellulose molecule, and about 25% of tetrapotassium pyrophosphate.

3. A composition as set forth in claim 2 containing about 3% of analkali metal silicate and having a pH of about 12.

4. A composition as set forth in claim 2 having a pH of about 12.

References Cited in the file of this patent UNITED STATES PATENTS Re.23,840 Vitale June 15, 1954 2,002,613 Orthner May 28, 1935 2,581,677Machlis Jan. 8, 1952 2,618,607 Sanders Nov. 18, 1952 FOREIGN PATENTS678,445 Great Britain -n Sept. 3, 1952

1. A CONTROLLED SUDSING HEAVY DUTY LIQUID DETERGENT COMPOSITION WHICHHAS PHASE STABILITY ON STORAGE AND SUDS STABILITY IN USAGE CONSISTINGESSENTIALLY OF AN AQUEOUS SUSPENSION OF FROM ABOUT 2% TO ABOUT 3% OFPOTASSIUM DODECYIBENZENE SULFONATE, FROM ABOUT 3.5% TO ABOUT 5% OFSODIUM TALLOW METHYL TAURATE, FROM ABOUT 2% TO ABOUT 3 OF AN ALKALIMETAL SYLENE SULFONATE, BOUT 1% OF COCONUT OIL FATTY ACIDS, ABOUT 1% OFTHE CONDENSATION PRODUCT OF ONE MOLE OF LAURIC MONOETHANOLAMIDE WITH ONEMOLE OF ETHYLENE OXIDE, ABOUT 1% OF TRIETHANOLAMINE, ABOUT 0.3% OFSODIUM CARBOXYMETHYLCELLULOSE, ABOUT 0.7% OF METHYLCELLULOSE, AND FROMABOUT 22.5% TO ABOUT 2K% OF TETRAPOTASSIUM PYROPHOSPHATE.